bi-level tenons - good? bad?

[Zeno Marx]

https://rebornpipes.files.wordpress.com/2016/09/bank25.jpg?w=625

I hope everyone can see that. If not, click the link. I don't know what you'd call this type of tenon, so I'll call it a bi-level. On some level, these seem like they'd be a good idea. They'd have to be fit well, and of course, there's the added difficulty of doing so. On the other hand, maybe this added surface screws with the fluid dynamics too much? Over-complicating what should be a relatively simple idea? I've only had a couple pipes with tenons like this, and I believe they were both low- to mid-grade English pipes from the 70s and maybe 80s. Maybe that should tell me all I need to know? Then again, I also remember these pipes smoking really well, like many of those old English buckets and seconds do. I knew a guy who used to clip off that second surface with wire cutters. He wasn't exactly the most discerning smoker I've ever met, so I don't know why he did it. Just did.

 

[Sasquatch]

To convince me that it's good, you'd have to show me how it improves the fit compared to a traditional tenon/mortise assembly. I consider every pipe I've had with that kind of "nipple" tenon to be an absolute dog of a smoker - I'd far rather see a deep funnel in a regular tenon.

 

[Ocelot55]

Around here we call them "stepped tenons," and you see them on everything from no name basket pipes to higher end English stuff, post 60's GBDs for example. I've never really understood if there was ever a purpose. In 99% of the cases I've seen the mortise was not double drilled to mirror the tenon. Back in the days when filter pipes and contraptions were all the rage, it was very common for the mortise and draft hole to be drilled and a third somewhere in size between the two drilled most of the way into the pipe to accommodate the filter/innertube/stinger. This created a series of three holes drilled from largest to smallest from shank to bowl. Sometimes you'll find a pipe whose step fits inside (never snugly, I might add) that second hole.

I have another theory, but it is only speculation. If you look at premolded stems, even today, that step is cast on many. I think there are several other possible functions for the step: as a size gauge, something to help facilitate the molding process, or for the purposes of lot identification. I'm sure there are those out there that know, but I've never heard a good explanation.

All that said, nothing beats a simple non-stepped tenon.

 

[Zeno Marx]

Thanks for the feedback. "Keep it simple, Stupid." and then "Work smart, not hard."

 

[huffelpuff]

I've had a few of those over the years that never smoked up to their potential. I always ended up taking a spade bit in a drill and removed them from the front opening up a nice funnel at the same time. They all smiles much better after this treatment crude as it is lol.

Jim

 

[Fr_Tom]

In 99% of the cases I've seen the mortise was not double drilled to mirror the tenon.

This was what I was wondering.

 

[hobie1dog]

That's the first one I've ever seen.